Final answer:
The most likely effect of excess sodium chloride in soil on plant tissue is cell dehydration and damage. High concentrations of sodium chloride can draw water out of plant cells and sodium can reach toxic levels within the plant.
Step-by-step explanation:
The most likely effect on plant tissue of an excess of sodium chloride in soil is C) Cell dehydration and damage. In environments with high salinity, such as saline soils commonly found in arid regions or soils affected by sodium accumulation due to irrigation, plants face significant stress. Sodium chloride in the soil affects the solute concentration in the soil solution.
This increased salinity can draw water out of plant root cells, leading to cell dehydration. Since plants have a limited ability to actively acquire sodium, when present in high concentrations, sodium can 'leak' into the plant cells, necessitating mechanisms to excrete sodium and sequester it within vacuoles. In contrast to its effects on water balance, sodium is not essential for most plants, and high concentrations can be toxic, impairing plant growth and health.